Rheostat



w. L. B LiSS.

RHEOSTAT.

APPLICATION FILED MAY 13. 1918.

1,327, 1 35, Patented J an. 6, 1920.

WITNESS: IN VEN TOR.

PVZZZz'am L. Elias.

A TTORNE Y.

Ur ah sra'rs ATENT OF TOE.

VIILLIAM L. BLISS, OF NIAGARA FALLS, NEW YORK, ASSIGNOB, TO U. S. LIGHT & HEAT CORPORATION, OF NIAGARA FALLS, NEW YORK, A CORPORATION OF NEW YORK.

RHEOSTAT.

Application filed May 13, 1918.

To all whom it may concern:

Be it known that I, WVILLIAM L. BLIss, a citizen of the United States, residing at Niagara Falls, in the county of Niagara and State of New York, have invented new and useful Improvements in Rheostats, of which the following is a specification.

The present invention relates to rheostats.

An object of the present invention is to provide a rheostat of which the adjustment may be readily accomplished and wherein there will be small likelihood of relative movement of the parts when said relative movement is not desired.

A further object of the present inventionis to provide a rheostat in which a movable member may be adjusted readily by hand and which will stay where it is placed, not withstanding considerable vibration.

A further object is to provide a rheostat which is simple in construction and cheap to manufacture.

Further objects will be apparent as the description proceeds.

Referring to the drawings- Figure 1 represents partly in section an end View of one embodiment of the present invention.

Fig. 2 represents a side view of the embodiment illustrated in Fig. 1.

Figs. 3, 4, 5 and 6 show details of the em bodiment illustrated in Figs. 1 and 2.

The numeral 1 indicates a cylindrical member whichmay be constructed of fiber, hard rubber, porcelain or other suitable insulating material. Said cylindrical member 1 may be grooved spirally to receive a resistance element 2 which may be coiled upon the cylinder member 1 in a plurality of convolutions. One or both ends of the resistance element 2 may be connected to an electric circuit.

Mounted upon the cylindrical member 1 in a position to contact with the resistance element 2 is a contact member 3. Said con tact member 3 is mounted to encircle the resistance element 2 and is spring-pressed into engagement therewith in a manner which will be described hereinafter. The contact member 3 comprises a plurality of arcuate sections 4, 4, whose inner surface conforms in general to the cylindrical outline of the resistance element 2. Each of the sections 4, 4, is substantially channel-shaped in crosssection whereby to provide a groove or chan- Patented Jan. 6, 1920.

Serial No. 234,117.

lessen the interior diameter of the contact.

member 3.

One of the sections 4, 4, is provided with a pair of outstanding ears 7, 7, which are adapted to embrace a handle 8. The sections 4, 4, and the split ring 5 should be made of conducting material. One of the ears 7 may be connected through the lead 9 to an electrical circuit.

In mounting the contact member 4 upon the resistance element 2, it will be obvious that the sections 4, 4, may be slipped inside of the split ring 5, whereby to encircle said resistance element 2. If desired, one of the sections 4 may be provided with a pin, not shown, which may fit within a small hole 10 in the split ring 5, whereby to prevent any considerable relative movement between the split ring 5 and the sections 4, 4. The sections 4, 4, it will be noted, should be of such a length that the springs 6, 6, may press said sections 4, 4, into intimate contact with said resistance element 2.

The contacting member 3 may be easily moved longitudinally of the cylindrical member 1 by turning said contact member 3 back and forth through a small arc, at the same time, urging the handle 8, with a small amount of pressure, in the direction in which it is desired to move the contact member. Though the contact member 3 may be readily moved along r.the resistance element 2 in the manner just described, there will be little or no tendency for the contact member 3 to move when the operator has removed his hand from the handle 8. The springs 6, 6, will urge sections 4, 4, to tightly grip the resistance element 2, whereby contactmemher 3 will stay where it is placed.

The arrangement illustrated wherein the springs 6, 6, urge contact member 3 into holding engagement with the resistance element 2, is preferable to a clamping arrangement whereby the contact member 3 is tightly clamped by means of bolts, or otherwise, around the resistance element 2. H the contact member 3 were secured by bolts or other securing means, after having its position adjusted longitudinally of the member 1, the resistance would be materially changed when the bolts were tightened up. According to the arrangement illustrated herein, however, no further tightening is required after the contact member 3 is moved to its proper position longitudinally of the member 1. Ready adjustment of the resistance of the rheostat is thereby provided, without danger of the parts slipping from their adjusted position. Substantially uniform contact is provided around the resistance element 2.

One embodiment of the present invention is described in detail. Many modifications will occur to those skilled in the art. It is intended in this patent to cover all such modifications that come Withinthe scope of the present invention as defined by the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States, is

l. A rheostat comprising an exposed re sistance element and a contact member, said member comprising a plurality of sections encircling and contacting with said element, and means for yieldingly holding said sections together and pressing them into elec-.

trical contact with said resistance element.

2. A rheostat comprising an exposed re sistance element and an adjustable contact member, said member comprising a plurality of sections yieldingly held together to form an annular member encircling and yieldingly gripping said element throughout the inner surface of said annular member.

3. A rheostat comprising, in combination, a cylindrical member, a resistance member coiled around said cylindrical member in a plurality of convolutions, a contact member encircling said cylindrical member and c0ntacting with said resistance member, said contact member comprising a plurality of arcuate shaped sections substantially channel-shaped in cross-section, and springs lying in the channel provided by said arcuate shaped sections.

4. A rheostat comprising, in combination, a cylindrical member, a resistance member coiled around said cylindrical member in a plurality of convolutions, a contact member encircling and contacting with said resistance member, said contact member comprising a plurality of arcuate shaped sections encircling said resistance member, said sections being channel-shaped in outline, and a. split ring lying in the channel formed by said arcuate shaped sections.

5. A rheostat comprising, in combination, a cylindrical member, a resistance member coiled around said cylindrical member in a plurality of convolutions, a contact member encircling and contacting with said resistance member, said contact member comprising a plurality of arcuate shaped sections encircling said resistance member, said sections being channel-shaped in outline, a split ring lying in the channel formed by said arcuate shaped sections, and. spring means encircling said split ring and lying in said channel.

6. A rheostat comprising, in combination, a cylindrical member, a resistance member coiled around said cylindrical. member in a plurality of convolutions, a contact member encircling said cylindrical member and contacting with said resistance member, said contact member comprising a plurality of arcuate shaped sections substantially channel-shaped in cross-section, and springs lying in the channel provided by said arcuate shaped sections, one of said sections being provided with an electric terminal.

7. A. rheostat comprising, in combination, a cylindrical resistance member and a contact member encircling said cylindrical mem her and contacting therewith, said contact member comprising a plurality of arcuate shaped sections, and means for insuring good electrical connection between said sections. 8. A rheostat comprising, in combination, a cylindrical resistance member and a contact member encircling said cylindrical member and contacting therewith, said contact member comprising a plurality of arcuate shaped sections, means for insuring good electrical connection between said sections, and means tending to lessen the diameter of said contact member.

In witness whereof, I have hereunto subscribed my name.

WILLIAM L. BLISS. 

